Digitizing tablet

A digitizing tablet, also called a graphics tablet, a graphics pad or drawing tablet, is a computer input device that allows you to hand-draw images and graphics, similar to the way one draws images with a pencil and paper. In a CAD program a digitizing tablet can be used to trace paper drawings into a drawing file or to launch drawing commands from a digitizing tablet overlay.

The TABLET command configures and calibrates a digitizing tablet and toggles the tablet mode.

This command requires that Wintab32.dll from Wacom Technology, Corp. be installed on the computer. Download Wintab32.dll from the internet, then place the file in your system directory: C:\Windows\System32.

Using a digitizing tablet in BricsCAD

In order to prepare BricsCAD for the use of a digitizing tablet, do the following:

  • Install the appropriate driver for your tablet.
  • Make sure Wintab32.dll is present in C:\Windows\System32.
  • Download the tablet overlay and CUI files.
  • Print the BricsCAD tablet overlay.
  • Load the overlay CUI file.
  • Start BricsCAD, then initialize the tablet.
  • Configure the tablet: part of the tablet surface is used as the menu area, another part of it is used as the screen pointing area.
  • Calibrate the tablet: a calibrated tablet can be used to trace the geometry of a paper drawing or image into a Bricscad drawing.

Downloading the tablet overlay and the CUI files

Click here to download the file Tablet.zip.

https://www.bricsys.com/bricscad/tools/Tablet.zip

The ZIP file contains the following files:

  • overlay.png: an image of the tablet overlay

  • overlay(A3).pdf: to print the tablet overlay on a A3 paper size.

  • overlay(cm).dwg: a DWG in which the overlay.png is attached as an image.

    The drawing contains two layouts to print the overlay using decimal units.

  • overlay(inch).dwg: a DWG in which the overlay.png is attached as an image.

    The drawing contains two layouts to print the overlay using imperial units.

  • tablet.cui: a partial cui file to be used with a tablet.

  • tablet(acadLike).cui: an AutoCAD-like partial cui file to be used with a tablet.

Loading the overlay CUI file

  1. Extract the overlay CUI files to the Support folder of the roamable root folder (see BricsCAD User Files).
  2. Load Tablet.cui as a partial CUI. The next time you start BricsCAD, Tablet.cui will be loaded automatically.
Note:
  • Please make sure the overlay.png image file is extracted to the same folder as the DWG's.
  • It may be necessary to repeat the above procedure after upgrading BricsCAD.

Switching the tablet ON / OFF

Do one of the following:

  • Click the TABLET field in the Status bar.
  • Press the F4 function key.
  • Launch the TABLET command.

Configuring the tablet

  1. Launch the TABLET command.

  2. Choose the Configure option.

  3. You are prompted: Do you want to align the tablet overlay? Yes/No/<No>.

    Type Y in the Command line and press Enter or choose Yes in the prompt menu.

    You are prompted: Digitize upper left corner of the overlay.

  4. Click on the mark in the upper left corner (1) of the digitizing tablet overlay.


    You are prompted: Digitize the lower left corner of the overlay.

  5. Click on the mark in the lower left corner (2) of the digitizing tablet overlay.

    You are prompted: Digitize the lower right corner of the overlay.

  6. Click on the mark in the lower right corner (3) of the digitizing tablet overlay.

    You are prompted: Digitize the lower left corner of the screen pointing area.

  7. Click on the mark at position (4) on the of the digitizing tablet overlay.

    You are prompted: Digitize the upper right corner of the screen pointing area.

  8. Click on the mark at position (5) on the of the digitizing tablet overlay.

    You are prompted: Tablet configured.

Calibrating the tablet

To calibrate the digitizing tablet you must specify at least two points. The more additional points you specify, the more accurate the digitizing process. Additional points are particularly recommended when digitizing a non-orthogonal image, such as an aerial photograph.

  1. Launch the TABLET command.

  2. Choose the Calibrate option.

  3. You are prompted: Digitize point #1:

    Click a point on the digitizing tablet.

    You are prompted: Enter coordinates for point #1:

  4. Do one of the following:
    • Click a point in the BricsCAD drawing window.
    • Enter the coordinates (X,Y) in the Command line.
  5. Repeat step 3 to specify the following calibration point.

    You are prompted: Digitize point #3 (or ENTER to end):

  6. Do one of the following:
    • Repeat step 4 to specify an additional calibration point. (You can specify up to 10 calibration points.)
    • Press Enter to conclude the calibration process.
  7. BricsCAD responds:
    • When 2 calibration points are specified: Tablet calibrated.
    • When 3 or more than 4 calibration points are specified: Select transformation type Orthogonal/Affine:
    • When 4 calibration points are specified: Select transformation type Orthogonal/Affine/Projective:


  8. Select the transformation type.

    Transformation refers to the calculation of the points on the screen that correspond to points you digitize on the tablet.



    • Orthogonal (left): To be used with accurate paper drawings. Orthogonal transformation maintains all angles and preserves relative distances. If only two calibration points are specified, orthogonal transformation is generated automatically.
    • Affine (middle): Maintains parallel lines, but not necessarily the angles between intersecting lines.
    • Projective (right): Does not maintain parallel lines, nor angles.